Phenolic thiane derivatives

ABSTRACT

Phenolic thiane derivatives of the formula I or II ##STR1## in which n is 0, 1 or 2 and R 2 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , T and Z are as defined in claim 1, are effective stabilizers for color photography recording materials, in particular for the yellow layer. They act not only as light stabilizers but also as stabilizers against thermal oxidation.

The present invention relates to novel phenolic derivatives of tetrahydrothiopyran (thiane) and their use as stabilizers for colour photography recording materials.

These are compounds of the formula I or II ##STR2## in which n is 0, 1 or 2, R¹ and R² independently of one another are hydrogen or methyl, R³ and R⁴ independently of one another are hydrogen, C₁ -C₄ alkyl, phenyl, thienyl or phenyl which is substituted by 1 or 2 C₁ -C₈ alkyl groups, cyclohexyl, phenyl, C₇ -C₉ phenylalkyl, hydroxyl, C₁ -C₁₈ alkoxy or halogen, R⁵ and R⁶ independently of one another are hydrogen, C₁ -C₄ alkyl, phenyl, --COO(C₁ -C₁₈ alkyl), --CO--CH₃ or --CO-phenyl, R⁷ is hydrogen, C₁ -C₈ alkyl or one of the groups --CO--R¹¹, --CO--COO(C₁ -C₄ -alkyl), --SO₂ --R¹², --CON(R¹³)(R¹⁴), --Si(R¹⁵)(R¹⁶)R¹⁷) or ##STR3## R⁸ and R⁹ independently of one another are hydrogen, C₁ -C₁₂ alkyl, C₇ -C₉ phenylalkyl, C₅ -C₈ cycloalkyl or phenyl, R¹⁰ is hydrogen, --OR⁷ or a group of the formula III ##STR4## in which M is a direct bond, --O--, --S--, --S--S--, --CH₂ --, --CH(C₁ -C₈ alkyl)-or --C(CH₃)₂ --, R¹¹ is C₁ -C₂₀ alkyl, C₃ -C₂₀ alkenyl, C₅ -C₁₂ cycloalkyl, C₇ -C₁₃ phenylalkyl or C₆ -C₁₀ aryl, R¹² is C₁ -C₁₂ alkyl, C₆ -C₁₀ aryl or C₇ -C₂₄ alkylaryl, R¹³ is hydrogen, C₁ -C₁₂ alkyl or cyclohexyl, R¹⁴ is C₁ -C₁₂ alkyl, C₆ -C₁₀ aryl, C₁ -C₁₂ alkylsubstituted C₆ -C₁₀ aryl or cyclohexyl, or R¹³ and R¹⁴, together with the N atom, form a 5- or 6-membered saturated heterocyclic ring, R¹⁵, R¹⁶ and R¹⁷ independently of one another are C₁ -C₁₂ alkyl, C₃ -C₁₂ alkenyl, phenyl, cyclohexyl or benzyl, T is a trivalent group which completes the ring to give a thiane ring and is one of the following groups: ##STR5## in which R¹⁸ is hydrogen, C₁ -C₁₂ alkyl, benzyl, cyclohexyl or phenyl and R¹⁹ is hydrogen or C₁ -C₄ alkyl, Z is a divalent bonding member between T and the phenol radical and is one of the following groups: ##STR6## the carbonyl group of which is bonded to T and in which R²⁰ is C₁ -C₁₄ -alkylene, R²¹ is hydrogen, C₁ -C₁₂ alkyl, phenyl, C₇ -C₉ phenylalkyl or a group of the formula IV ##STR7## and R²² is a group --O(C₁ -C₄ alkyl) or a group of the formula V ##STR8##

Where these substituents are alkyl or alkylene, these groups can be unbranched or branched. If R¹³ and R¹⁴, together with the N atom, form a saturated heterocyclic ring, they can additionally also contain an O, N or S atom. Examples are a pyrrolidine, piperidine, morpholine or piperazine ring, which can be substituted by one or two C₁ -C₄ alkyl groups.

Preferred compounds of the formula I or II are those in which n is 0 or 2, R¹ and R² are hydrogen or methyl, R³ and R⁴ independently of one another are methyl, phenyl, thienyl or phenyl which is substituted by one or two C₁ -C₄ alkyl groups, cyclohexyl, hydroxyl, C₁ -C₄ alkoxy or chlorine, R⁵ and R⁶ independently of one another are hydrogen, --COO(C₁ -C₄ alkyl) or --COOCH₃, R⁷ is hydrogen or a group --CO--R¹¹, --CO--COO(C₁ -C₄ -alkyl), --Si(CH₃)₃ or ##STR9## R⁸ and R⁹ independently of one another are C₁ -C₈ alkyl, C₇ -C₉ phenylalkyl, cyclohexyl or phenyl, R¹⁰ is hydrogen, --OR⁷ or a group of the formula III, in which M is --S--, --CH₂ --, --CH(C₁ -C₄ alkyl) or --C(CH₃)₂ --, R¹¹ is C₁ -C₁₂ alkyl or phenyl, T is one of the following trivalent groups: ##STR10## in which R¹⁹ is C₁ -C₄ alkyl, and Z is one of the following divalent groups: ##STR11## the carbonyl group of which is bonded to T and in which R²⁰ is C₁ -C₁₄ the alkylene, R²¹ is C₁ -C₈ alkyl, benzyl or a group of the formula IV and R²² is a group --O(C₁ -C₄ alkyl) or a group of the formula V.

Particularly preferred compounds of the formula I and II are those in which n is 0 or 2, R¹ and R² are hydrogen or methyl, R³ and R⁴ are methyl, phenyl, thienyl or phenyl which is substituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, hydroxyl or chlorine, R⁵ and R⁶ are hydrogen, R⁷ is hydrogen or a group ##STR12## R⁸ and R⁹ independently of one another are hydrogen, C₁ -C₄ alkyl, cyclohexyl or phenyl, R¹⁰ is hydrogen, T is one of the following trivalent groups: ##STR13## in which R¹⁹ is C₁ -C₄ alkyl, and Z is one of the following divalent groups: ##STR14## the carbonyl group of which is bonded to T and in which R²⁰ is C₁ -C₈ -alkylene, R²¹ is C₁ -C₈ alkyl, benzyl or a group of the formula IV and R²² is --O(C₁ -C₄ alkyl) or a group of the formula V.

Preferred compounds of the formula I and II are those in which R¹, R², R⁵ and R⁶ are hydrogen.

The sulfur in the thiane ring can be present as sulfide, sulfoxide or sulfone sulfur, depending on whether n is zero, 1 or 2. n is preferably zero or 2, and in particular zero.

Compared with the compounds of the formula II, the compounds of the formula I are preferred.

Examples of compounds of the formula I are:

(1) 4-(3,5-di-tert-butyl-4-hydroxybenzoyloxy)-thiane

(2) 4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxy]-thiane

(3) 4-(3,5-di-tert-butyl-4-hydroxybenzoyloxy)-2,2,6,6-tetramethylthiane

(4) 4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxy]-2,2,6,6-tetrametylthiane

(5) 4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxy]-1-oxo-2,2,6,6-tetramethylthiane

(6) 4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxy]-1,1-dioxo-2,2,6,6-tetramethylthiane

(7) 4-[5,5-dimethyl-5-(2-hydroxy-5-methoxyphenyl)-valerianyloxy]-2,2,6,6-tetramethylthiane

(8) 4-[α,α-bis(3,5--di-tert-butyl-4-hydroxybenzyl)-α-methoxycarbonylacetoxy]-2,2,6,6-tetramethylthiane

(9) 4-(3,5-di-tert-butyl-4-hydroxybenzoyloxy)-2,6-diphenylthiane

(10) 4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxy]-2,6-diphenylthiane

(11) N-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxy]-2,6-diphenylthiane-4-hydrazone

(12) 4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxy]-1,1-dioxo-2,6-diphenylthiane

(13) 4-[3-(3-methyl-4-hydroxy-5-tert-butylphenyl)-propionyloxy]-1,1-dioxo-2,6-diphenylthiane

(14) N-[3-(3-methyl-4-hydroxyphenyl-5-tert-butylphenyl)-propionyloxy]-2,6-diphenylthiane -4-hydrazone

(15) 1,4-dioxa-3-(3,5-di-tert-butyl-4-hydroxybenzoyloxmethyl)-7,9-diphenyl-8-tetra[4.5]spirodecane

(16) 1,4-dioxa-3-[β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxymethyl]-7,9-diphenyl-8-thia[4.5]spirodecane

(17) 1,4-dioxa-3-[β-(3-methyl-4-hydroxy-5-tert-butylphenyl)-propionyloxymethyl]-7,9-diphenyl-8-thia[4.5]spirodecane

(18) 1,5-dioxa-3-ethyl-(3,5-di-tert-butyl-4-hydroxybenzoyloxymethyl)-8,10-diphenyl-9-thia[5.5]spiroundecane

(19) 1,5-dioxa-3-ethyl-3-[β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxymethyl]-8,10-diphenyl-9-thia-[5.5]spiroundecane

(20) 1,5-dioxa-3-ethyl-3-[β-(3-methyl-4-hydroxy-5-tert-butylphenyl)propionyloxymethyl]-8,10-diphenyl-9-thia[5.5]spiroundecane

(21) 1,5-dioxa-3-ethyl-3-[β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxymethyl]-8,10-diphenyl-9-thia-9,9-dioxo[5.5]spiroundecane

(22) 1,5-dioxa-3-ethyl-3-[β-(3-methyl-4-hydroxy-5-tert-butylphenyl)propionyloxymethyl]-8,10-diphenyl-9-thia-9,9-dioxo[5.5]spiroundecane

(23) 1,5-dioxa-3-ethyl-3-[α-(3,5-dioxymethyl]tert-butyl-4-hydroxyphenoxy)-acetyloxymethyl]-8,10-diphenyl-9-thia[5.5]undecane

(24) 1,5-dioxa-3-ethyl-3-[β-(3-methyl-4-methyloxalyloxy-5-tert-butylphenyl)-propionyloxymethyl]-8,10-diphenyl-9-thia[5.5]undecane

(25) 1,5-dioxa-3-ethyl-3-[β-(3-methyl-4-trimethylsiloxy-5-tert-butyl)propionyloxymethyl]-8,10-diphenyl-9-thia[5.5]undecane

(26) 1,5-dioxa-3-ethyl-3-[5,5-dimethyl-5-(2-hydroxy-5-methoxyphenyl)valeryloxymethyl]-8,10-diphenyl-9-thia[5.5]undecane

(27) 1,5-dioxa-3-ethyl-3-[2-(3-tert-butyl-4-hydroxyphenyl)-tetradecanoyloxymethyl]-8,10-diphenyl-9-thia[5.5]undecane

(28)1,5-dioxa-3-ethyl-3-[5,5-dimethyl-5-(2-hydroxy-3,5-dimethylphenyl)valeryloxymethyl]-8,10-diphenyl-9-thia[5.5]undecane

(29) 1,5dioxa-3ethyl-3-[5,5-dimethyl-5-(3-methyl-4hydroxyphenyl)valeryloxymethyl]-8,10-diphenyl-9-thia[5.5]undecane

(30) 1,5-dioxa-3-ethyl-3-[5,5-dimethyl-5-(2-hydroxy-5-tert-butylphenyl)valeryloxymethyl]-8,10-diphenyl-9-thia[5.5]undecane

(31) 1,5-dioxa-3-ethyl-3-[5,5-dimethyl-5-(3,5-dimethyl-4-hydroxyphenyl)-valeryloxymethyl]-8,10-diphenyl-9-thia[5.5]undecane

(32) 1,5-dioxa-3-ethyl-3-[5,5-dimethyl-5-(2-methyloxalyloxy-3,5-dimethyl)valeryloxymethyl]-8,10-diphenyl-9-thia[5.5]undecane

(33) 1,5-dioxa-3-ethyl-3-[5,5-dimethyl-5-(3,5-di-tert-butyl-4-hydroxyphenyl)-valeryloxymethyl]-8,10-diphenyl-9-thia[5.5]undecane

(34) 4-(3,5-di-tert-butyl-4-hydroxybenzoyloxy)-2,6-di(4-chlorophenyl)thiane

(35) 4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxy]-2,6-di(4-chlorophenyl)-thiane

(36) 4-[3-(3-methyl-4-hydroxy-5-tert-butylphenyl)-propionyloxy]-2,6-di(4-chlorophenyl)-thiane

(37) 4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxy]-2,6-di(4-methoxyphenyl)-thiane

(38) 1,5-dioxa-3-ethyl-3-(3,5-di-tert-butyl-4-hydroxybenzoyloxymethyl-8,10-di(4-chlorophenyl)-9-thia[5.5]undecane

(39) 1,5-dioxa-3-ethyl-3-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxymethyl]-8,10-di(4-chlorophenyl)-9-thia[5.5]undecane

(40)1,5-dioxa-3-ethyl-3-[3-(3-methyl-4-hydroxy-5-tert-butylphenyl)propionyloxymethyl]-8,10-di(4-chlorophenyl)-9-thia[5.5]undecane

(41) 1,5-dioxa-3-ethyl-3-[3-(3-methyl-4-hydroxy-5-tert-butylphenyl)propionyloxymethyl]-8,10-di(3-methyl-4-hydroxy-5-tert-butylphenyl)-9-thia [5.5]undecane

(42) 4-(3,5-di-tert-butyl-4-hydroxybenzoyloxy)-2,6-di(2-thienyl)-thiane

(43) 4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxy]-2,6-di(2-thienyl)-thiane

(44) 4-[3-(3-methyl-4-hydroxy-5-tert-butylphenyl)-propionyloxy]-2,6-di(2-thienyl)-thiane

(45) 1,5-dioxa-3-ethyl-3-[β-(3-tert-butyl-4-hydroxyphenyl)-propionyloxymethyl]-8,10-diphenyl-9-thia[5.5]spiroundecane

(46) 1,5-dioxa-3-ethyl-3-[β-(3-methyl-5-tert-butyl-4-[methyloxalyloxy]-phenyl)-propionyloxymethyl]-8,10-diphenyl-9-thia[5.5]spiroundecane

(47) 1,5-dioxa-3-ethyl-3-[β-(3-methyl-5-tert-butyl-4-[trimethylsiloxy]-phenyl)-propionyloxymethyl]-8,10-diphenyl-9-thia[5.5]spiroundecane

(48) N-[β-(3-methyl-4-hydroxy-5-tert-butylphenyl)-propionylamido]-2,6- diphenyl-4-iminothiane

(49) N-[β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionylamido]-2,6-diphenyl-4-iminothiane

(50) methyl 2,2,6,6-tetramethylthian-4-yl bis-(3,5-di-tert-butyl-4-hydroxybenzyl)-malonate

(51) di(2,2,6,6-tetramethylthian-4-yl) bis-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate

(52) the compound of the formula ##STR15##

Examples of compounds of the formula II are the compounds of the following formulae: ##STR16##

The compounds of the formula I or II can be prepared by reacting a phenolic carboxylic acid or derivative thereof VI with an OH-- or NH-- functional thiane derivative VII: ##STR17##

Compounds of the formula II are prepared analogously by reacting a phenolic dicarboxylic acid or derivative thereof VIII with 2 equivalents of VII: ##STR18##

If VII is an OH-functional thiane derivative, the reaction is carried out under the customary conditions of esterification (D=OH), transesterification (D=O-alkyl) or O-acylation (D=Cl). The esterification is preferably carried out under acid catalysis and the transesterification under basic catalysis. The 0-acylation by means of the carboxylic acid chloride is preferably carried out in the presence of equivalent amounts of a base.

The phenolic carboxylic acids and their derivatives of the formula VI and VIII are known compounds or can be prepared by methods which are known per se.

The functional thianes of the formula VII are in some cases known compounds or can be prepared by processes analogous to known processes. Thus, compounds of the formula VII in which >T--H is a group >CH--OH can be obtained by reduction of the corresponding ketones with borohydrides in accordance with the method of J. Klein, H. Stollar/Tetrahedron 30, 2541 (1974) or K. Ramalingam et al./J. Org. Chem. 44, 477 (1979). Compounds of the formula VII in which >T--H is a group >--CH--NH₂ can be prepared by reduction of the oximes >C═NOH with LiAlH₄ in accordance with the method of P. K. Subramanian et al./J. Org. Chem. 46, 4376 (1981). Compounds of the formula VII in which T--H is a group >C═N--NH₂ are obtained by reaction of the corresponding thianones with hydrazine. Compounds of the formula VII in which T--H is a group ##STR19## can be obtained by ketalization of the corresponding thianones with glycerol or with a polyol of the formula R¹⁹ --C(CH₂ OH)₃.

The cyclic sulfoxides and sulfones of the formula I or II in which n is 1 or 2 can be obtained from the thiane derivatives where n=0 by oxidation, such as is described, for example, by J. Klein, H. Stollar/Tetrahedron 30, 2541 (1974) and P.K. Subramanian et al./J. Org. Chem. 46, 4376 (1981).

Compounds of the formula I in which T is a group >C═N--NH-- can also be prepared by reaction of a thianone IX with a hydrazide of a phenolic carboxylic acid X: ##STR20##

The compounds of the formula I or II can be used as stabilizers for colour photography recording materials. These materials are predominantly papers or films which contain three photosensitive layers, the yellow layer, the magenta layer and the cyan layer. These layers are gelatin layers which contain at least one silver halide and one dye coupler and can also contain other additives. The compounds of the formula I or II are added to such a gelatin layer. For this, they are dissolved in an organic solvent or solvent mixture and the solution is emulsified in a gelatin solution, which is then added to the photographic gelatin layer during preparation thereof. The solvent used is preferably a mixture of a low-boiling and a high-boiling solvent and the low-boiling solvent is removed during the emulsification.

The stabilizer solution can be dispersed in the gelatin solution, for example, in a colloid mill or in a homogenizer or with the aid of ultrasound. Surface-active agents (emulsifiers) can also be added here. A fine dispersion is a prerequisite for homogeneous distribution of the stabilizers in the photographic layer.

The compounds of the formula I or II stabilize both the colour couplers and the photographic dyes formed after exposure and development from the effect of light. They prevent or delay the bleaching or change in colour of the photographic dyes by the action of light. They do not react with the customary dye couplers and do not impede the photographic process of colour formation.

Phenolic compounds have already been proposed as stabilizers for colour photography materials, thus, for example, in EP-A-82,817, EP-A-103,540, U.S. Pat. No. 3,935,016 or EP-A-113,124. Such stabilizers have led to a considerable increase in the light-fastness of colour photographs, but there is continued interest in an improvement in the stabilization.

The stabilizers of the formula I or II are expediently added in an amount of up to 1 g/m² per colour layer, preferably 10 to 300 mg/m². They can be added to one, two or all three colour silver layers. The addition to the yellow layer is of particular importance. The layers contain the sensitized silver halide and the respective colour coupler. The layers can also contain further stabilizers and/or other additives.

The yellow couplers are preferably compounds of the formula XI ##STR21## in which R₁ is alkyl or aryl, R₂ is aryl and Q is hydrogen or a group which can be split off by reaction with the oxidized developer.

A group of yellow couplers comprises those compounds of the formula XI in which R₁ is tert-butyl and R₂ is a group of the formula ##STR22## in which R₃ is hydrogen, halogen, alkyl or alkoxy and R₄, R₅ and R₆ are hydrogen, halogen, alkyl, alkenyl, alkoxy, aryl, carboxyl, alkoxycarbonyl, a carbamoyl group, a sulfone or sulfamoyl group or an alkylsulfonamido group, acylamino group, ureido group or amino group.

Preferably, R₃ is chlorine, R₄ and R₅ are hydrogen and R₆ is an acylamino group. These also include the compounds of the formula ##STR23## in which x is 0-4, R₇ is hydrogen or alkyl and R₈ and R₉ are alkyl.

Another group of yellow couplers corresponds to the formula XII ##STR24## in which R₁₀ is hydrogen, halogen or alkoxy, R₁₁, R₁₂ and R₁₃ are hydrogen, halogen, alkyl, alkenyl, alkoxy, aryl, carboxyl, alkoxycarbonyl, a carbamoyl group or a sulfone group, sulfamoyl group, sulfonamido group, acylamino group, ureido group or amino group and R₁ and Q are as defined above.

These include compounds of the formula XII in which R₁ is tert-butyl, R₁₀ is chlorine, R₁₁ and R₁₃ are hydrogen and R₁₂ is alkoxycarbonyl.

In the compounds of the formula XI and XII, the leaving group Q can be hydrogen, or is a heterocyclic group ##STR25## in which R₁₄ is an organic divalent group which completes the ring to give a 4- to 7-membered ring, or Q is a group --OR₁₅, in which R₁₅ is alkyl, aryl, acyl or a heterocyclic radical.

Typical examples of customary yellow couplers are the compounds of the following formulae: ##STR26##

Further examples of yellow couplers are to be found in U.S. Pat. Nos. 2,407,210, 2,778,658, 2,875,057, 2,908,513, 2,908,573, 3,227,155, 3,227,550, 2,253,924, 3,265,506, 3,277,155, 3,408,194, 3,341,331, 3,369,895, 3,384,657, 3,415,652, 3,447,928, 3,551,155, 3,582,322, 3,725,072, 3,891,445, 3,933,501, 4,115,121, 4,401,752 and 4,022,620, in DE-A-1,547,868, 2,057,941, 2162,899, 2,163,813, 2,213,461, 2,219,917, 2,561,361, 2,261,362, 2,263,875, 2,329,587, 2,414,006 and 2,422,812 and in GB-A-1,425,020 and 1,077,874.

The yellow couplers are usually employed in an amount of 0.05-2 mol and preferably 0.1-1 mol per mol of silver halide.

Magenta couplers can be, for example, simple 1-aryl-5-pyrazolones or pyrazole derivatives condensed with 5-membered hetero rings, for example imidazopyrazoles, pyrazolopyrazoles, pyrazolotriazoles or pyrazolotetrazoles.

One group of magenta couplers comprises 5-pyrazolones of the formula XIII ##STR27## such as are described in British Patent Specification 2,003,473. In this formula, R₁₆ is hydrogen, alkyl, aryl, alkenyl or a heterocyclic group. R₁₇ is hydrogen, alkyl, aryl, a heterocyclic group or an ester group, alkoxy group, alkylthio group, carboxyl group, arylamino group, acylamino group, (thio)-urea group, (thio)-carbamoyl group, guanidino group or sulfonamide group.

Preferably, R₁₇ is a group ##STR28## in which R₁₈ is imino, acylamino or ureido, R₁₉ is hydrogen, halogen, alkyl or alkoxy and R₂₀ is hydrogen, alkyl, acylamino, carbamoyl, sulfamoyl, sulfonamido, alkoxycarbonyl, acyloxy or a urethane group.

If Q' is hydrogen, the magenta coupler is tetraequivalent with respect to the silver halide.

Typical examples of this type of magenta couplers are compounds of the formula ##STR29## in which R₂₀ is as defined above.

Further examples of such tetraequivalent magenta couplers are to be found in U.S. Pat. Nos. 2,983,608, 3,061,432, 3,062,653, 3,127,269, 3,152,896, 3,311,476, 3,419,391, 3,519,429, 3,558,319, 3,582,322, 3,615,506, 3,684,514, 3,834,908, 3,888,680, 3,891,445, 3,907,571, 3,928,044, 3,930,861, 3,930,866 and 3,933,500.

If Q' in formula XIII is not hydrogen but is a group which is eliminated in the reaction with the oxidized developer, the compound is a diequivalent magenta coupler. Q' can in this case be, for example, halogen or a group bonded to the pyrazole ring via O, S or N. Such diequivalent couplers give a higher colour density and are more reactive towards the oxidized developer than the corresponding tetraequivalent magenta couplers.

Examples of diequivalent magenta couplers are described in U.S. Pat. Nos. 3,006,579, 3,419,391, 3,311,476, 3,432,521, 3,214,437, 4,032,346, 3,701,783, 4,351,897 and 3,227,554, EP-A-133,503, DE-A-2,944,601 and JP-A-78/34044, 74/53435, 74/53436, 75/53372 and 75/122,935.

2 pyrazalone rings can be linked via a divalent Q' and so-called bis-couplers are then obtained. Such compounds are described, for example, in U.S. Pat. Nos. 2,632,702, 2,618,864, GB-A-968,461, GB-A-786,859 and JP-A-76/37646, 59/4086, 69/16110, 69/26589, 74/37854 and 74/29638. Y is preferably an O-alkoxyarylthio group.

As mentioned above, pyrazoles fused to 5-membered heterocyclic rings--so-called pyrazoloazoles--can also be used as magenta couplers. Their advantage over simple pyrazoles is that they have colours with a greater formalin resistance and purer absorption spectra.

They can be represented by the general formula XIV ##STR30## in which Z_(a), Z_(b) and Z_(c) are the radicals to complete a 5-membered ring, which can contain up to 4 nitrogen atoms. The compounds can accordingly be pyrazolo-imidazoles, pyrazolo-pyrazoles, pyrazolo-triazoles or pyrazolo-tetrazoles. R₁₇ and Q' are as defined in formula XIII.

Pyrazolo-tetrazoles are described in JP-A-85/33552; pyrazolo-pyrazoles are described in JP-A-85/43,695; pyrazolo-imidazoles are described in JP-A-85/35732, JP-A-86/18949 and U.S. Pat. No. 4,500,630; pyrazolo-triazoles are described in JP-A-85/186,567, JP-A-86/47957, JP-A-85/215,687, JP-A-85/197,688, JP-A-85/172,982, EP-A-119,860, EP-A-173,256, EP-A-178,789, EP-A-178,788 and in Research Disclosure 84/24,624.

Further pyrazoloazole magenta couplers are described in: JP-A-86/28,947, JP-A-85/140,241, JP-A-85/262,160, JP-A-85/213,937, EP-A-177,765, EP-A-176,804, EP-A-170,164, EP-A-164,130, EP-A-178,794, DE-A-3,516,996, DE-A-3,508,766 and Research Disclosure 81/20919, 84/24531 and 85/25758.

Cyan couplers can be, for example, derivatives of phenol, of 1-naphthol or of pyrazoloquinazolone. Structures of the formula XV ##STR31## in which R₂₁, R₂₂, R₂₃ and R₂₄ are hydrogen, halogen, alkyl, carbamoyl, amido, sulfonamido, phosphoramido or ureido, are preferred. R²¹ is preferably H or Cl and R₂₂ is preferably an alkyl or amido group. R₂₃ is preferably an amido group and R₂₄ is preferably hydrogen. Q" is hydrogen or a leaving group which is split off during the reaction with the oxidized developer. A detailed list of cyan couplers is to be found in U.S. Pat. No. 4,456,681.

Examples of customary cyan couplers are the following: ##STR32##

Further examples of cyan couplers are to be found in the following U.S. Pat. Nos.: 2,369,929, 2,423,730, 2,434,272, 2,474,293, 2,521,908, 2,698,794, 2,706,684, 2,772,162, 2,801,171, 2,895,826, 2,908,573, 3,034,892, 3,046,129, 3,227,550, 3,253,294, 3,311,476, 3,386,301, 3,419,390, 3,458,315, 3,476,560, 3,476,563, 3,516,831, 3,560,212, 3,582,322, 3,583,971, 3,591,383, 3,619,196, 3,632,347, 3,652,286, 3,737,326, 3,758,308, 3,839,044, 3,880,661, 4,004,929, 4,124,396, 4,333,999, 4,463,086 and 4,456,681.

The colour developers usually employed for colour photography materials are p-dialkylaminoanilines. Examples of these are 4-amino-N,N-diethylaniline, 3-methyl-4-amino-N,N-diethylaniline, 4-amino-N-ethyl-N-α-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-α-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-α-methanesulphonamidoethylaniline, 3-methyl-4-amino-N-ethyl-N-αmethoxyethyl-aniline, 3-α-methanesulphonamidoethyl-4-amino-N,N-diethylaniline, 3-methoxy-4-amino-N-ethyl-N-α-hydroxyethylaniline, 3methoxy-4-amino-N-ethyl-N-α-methoxyethylaniline, 3-acetamido-4-amino-N,N-diethylaniline, 4-amino-N,N-dimethylaniline, N-ethyl-N-α-[α-α-methoxyethoxy)ethoxy]ethyl-3-methyl-4-aminoaniline, N-ethyl-N-α-α-methoxyethoxy)ethyl-3-methyl-4-aminoaniline and the salts of such compounds, for example sulfates, hydrochlorides or toluenesulfonates.

The stabilizers according to the invention can be incorporated into the colour photography material together with the colour coupler and if appropriate further additives by predissolving them in high-boiling organic solvents. Solvents which have a boiling point above 160° C. are preferably used. Typical examples of such solvents are the esters of phthalic acid, phosphoric acid, citric acid, benzoic acid or fatty acids, and alkylamides and phenols.

A low-boiling solvent is usually additionally also used in order to facilitate incorporation of the additives into the colour photography material. Examples of such solvents are esters, for example ethyl acetate, alcohols, for example butanol, ketones, for example methyl isobutyl ketone, chlorohydrocarbons, for example methylene chloride, or amides, for example dimethylformamide. If the additives themselves are liquid, they can also be incorporated into the photographic material without the aid of solvents.

Further details on high-boiling solvents which can be used are to be found in the following Patent Specifications:

Phosphates: GB-A-791,219, BE-A-755,248 and JP-A-76/76739, 78/27449, 78/218,252, 78/97573, 79/148,113, 82/216,177, 82/93323 and 83/ 216,177.

Phthalates: GB-A-791,219 and JP-A-77/98050, 82/93322, 82/216,176, 82/218,251, 83/24321, 83/45699 and 84/79888.

Amides: GB-A-791,219, JP-A-76/105,043, 77/13600, 77/61089 and 84/189,556 and U.S. Pat. No. 928,741.

Phenols: GB-A-820,329, FR-A-1,200,657 and JP-A-69/69946, 70/3818, 75/123,026, 75/82078, 78/17914, 78/21166, 82/212,114 and 83/45699.

Other oxygen-containing compounds: US-A-3,748,141 and 3,779,765, JP-A-73/75126, 74/101,114, 74/10115, 75/101,625, 76/76740 and 77/61089 and BE-A-826,039.

Other compounds: JP-A-72/115,369, 72/130,258, 73/127,521, 73/76592, 77/13193, 77/36294 and 79/95233 and Research Disclosure 82/21918.

The amount of high-boiling solvent is in the range from 0.1 to 300%, preferably 10 to 100%, based on the colour coupler.

The photographic layers can furthermore contain colour fog inhibitors. These prevent the formation of colour fogs, such as are formed, for example, by reaction of the coupler with unintentionally oxidized developer or with by-products of the colour formation process. Such colour fog inhibitors are usually hydroquinone derivatives, but they can also be derivatives of aminophenols, of gallic acid or of ascorbic acid. Typical examples of these are to be found in the following Patent Specifications: U.S. Pat. Nos. 2,360,290, 2,336,327, 2,403,721, 2,418,613, 2,675,314, 2,701,197, 2,704,713, 2,728,659, 2,732,300 and 2,735,365; EP-A-124,877; and JP-A-75/92988, 75/92989, 75/93928, 75/110,337 and 77/146,235.

The photographic layers can also contain so-called DIR couplers which give colourless compounds with the oxidized developer. They are added to improve the sharpness and grain structure of the colour pictures.

The photographic layers can also contain UV absorbers. These filter out the UV light and thus protect the dyes, the couplers or other components from photodegradation. Examples of such UV absorbers are 2-(2-hydroxyphenyl)-benzotriazoles, 2-hydroxybenzophenones, salicylic acid esters, acrylonitrile derivatives or thiazolines. Such UV absorbers are described in more detail, for example, in the following Patent Specifications: U.S. Pat. Nos. 3,314,794, 3,352,681, 3,705,805, 3,707,375, 4,045,229, 3,700,455, 3,533,794, 3,698,907, 3,705,805 and 3,738,837 and JP-A-71/2784. Preferred UV absorbers are the 2-(2-hydroxyphenyl)-benzotriazoles.

The photographic layers can also contain phenolic compounds which act as light stabilizers for the colour picture and as agents against colour fog. They can be contained in a photosensitive layer (colour layer) or in an intermediate layer, by themselves or together with other additives. Such compounds are described in more detail in the following Patent Specifications: U.S. Pat. Nos. 3,700,455, 3,591,381, 3,573,052, 4,030,931, 4,174,220, 4,178,184, 4,228,235, 4,279,990, 4,346,165, 4,366,226, 4,447,523, 4,528,264, 4,581,326, 4,562,146 and 4,559,297; GB-A-1,309,277, 1,547,302, 2,023,862, 2,135,788, 2,139,370 and 2,156,091; DE-A-2,301,060, 2,347,708, 2,526,468, 2,621,203 and 3,323,448; DD-A-200,691 and 214,468; EP-A-106,799, 113,124, 125,522, 159,912, 161,577, 164,030, 167,762 and 176,845; JP-A-74/134,326, 76/127,730, 76/30462, 77/3822, 77/154,632, 78/10842, 79/48535, 79/70830, 79/73032, 79/147,038, 79/154,325, 79/155,836, 82/142,638, 83/224,353, 84/5246, 84/72443, 84/87456, 84/192,246, 84/192,247, 84/204,039, 84/204,040, 84/212,837, 84/220,733, 84/222,836, 84/228,249, 86/2540, 86/ 8843, 86/18835, 86/18836, 87/11456, 87/42245, 87/62157 and 86/6652 and in Research Disclosure 79/17804.

The photographic layers can also contain certain phosphorus-III compounds, in particular phosphites and phosphonites. These function as light stabilizers for the colour pictures and as a dark storage stabilizer for magenta couplers. They are preferably added to the high-boiling solvents, together with the coupler. Such phosphorus-III compounds are described in more detail in the following Patent Specifications: U.S. Pat. No. 4,407,935, U.S. Pat. No. 4,436,811, EP-A-181,289, JP-A-73/32728, JP-A-76/1420 and JP-A-55/67741.

The photographic layers can also contain organometallic complexes which are light stabilizers for the colour pictures, in particular for the magenta dyes. Such compounds and combination thereof with other additives are described in more detail in the following Patent Specifications: U.S. Pat. Nos. 40,050,938, 4,239,843, 4,241,154, 4,242,429, 4,241,155, 4,242,430, 4,273,854, 4,246,329, 4,271,253, 4,242,431, 4,248,949, 4,245,194, 4,268,605, 4,246,330, 4,269,926, 4,245,018, 4,301,223, 4,343,886, 4,346,165 and 4,590,153; JP-A-81/167,138, 81/168,652, 82/30834 and 82/161,744; EP-A-137,271, 161,577 and 185,506; and DE-A-2,853,865.

The photographic layers can also contain hydroquinone compounds. These act as light stabilizers for the colour couplers and for the colour pictures and as trapping agents for oxidized developer in intermediate layers. They are used in particular in the magenta layer. Such hydroquinone compounds and combinations thereof with other additives are described in more detail in the following Patent Specifications: U.S. Pat. Nos. 2,360,290, 2,336,327, 2,403,721, 2,418,613, 2,675,314, 2,701,197, 2,710,801, 2,732,300, 2,728,659, 2,735,765, 2,704,713, 2,937,086, 2,816,028, 3,582,333, 3,637,393, 3,700,453, 3,960,570, 3,935,016, 3,930,866, 4,065,435, 3,982,944, 4,232,114, 4,121,939, 4,175,968, 4,179,293, 3,591,381, 3,573,052, 4,279,990, 4,429,031, 4,346,165, 4,360,589, 4,356,167, 4,385,111, 4,416,978, 4,430,425, 4,277,558, 4,489,155, 4,504,572 and 4,559,297; FR-A-885,982; GB-A-891,158, 1,156,167, 1,363,921, 2,022,274, 2,066,975, 2,071,348, 2,081,463, 2,117,526 and 2,156,091; GB-A-2,408,168, 2,726,283, 2,639,930, 2,901,520, 3,308,766, 3,320,483 and 3,323,699; DE-A-216,476, 214,468 and 214,469, EP-A-84290, 110,214, 115,305, 124,915, 124,877, 144,288, 147,747, 178,165 and 161,577; and JP-A-75/33733, 75/21249, 77/128,130, 77/146,234, 79/70036, 79/133,131, 81/83742, 81/87040, 81/109,343, 83/134,628, 82/22237, 82/112,749, 83/17431, 83/21249, 84/75249, 84/149,348, 84/182,785, 84/180,557, 84/189,342, 84/228,249, 84/101,650, 79/24019, 79/2582, 86/48856, 86/48857, 86/27539, 86/6652, 86/72040, 87/11455 and 87/62157 and in Research Disclosure 79/17901, 79/17905, 79/18813, 83/22827 and 84/24014.

The photographic layers can also contain derivatives of hydroquinone ethers. These compounds act as light stabilizers and are particularly suitable for stabilizing magenta dyes. Such compounds and combination thereof with other additives are described in more detail in the following patent specifications:

U.S. Pat. Nos. 3,285,937, 3,432,300, 3,519,429, 3,476,772, 3,591,381, 3,573,052, 3,574,627, 3,573,050, 3,698,909, 3,764,337, 3,930,866, 4,113,488, 4,015,990, 4,113,495, 4,120,723, 4,155,765, 4,159,910, 4,178,184, 4,138,259, 4,174,220, 4,148,656, 4,207,111, 4,254,216, 4,314,011, 4,273,864, 4,264,720, 4,279,990, 4,332,886, 4,436,165, 4,360,589, 4,416,978, 4,385,111, 4,459,015 and 4,559,297; GB-A-1,347,556, 1,366,441, 1,547,392, 1,557,237 and 2,135,788; DE-A-3,214,567; DD-214,469; EP-A-161,577, 167,762, 164,130 and 176,845; and JP-A-76/123,642, 77/35633, 77/147,433, 78/126, 78/10430, 78/53321, 79/24019, 79/25823, 79/48537, 79/44521, 79/56833, 79/70036, 79/70830, 79/73032, 79/95233, 79/145,530, 80/21004, 80/50244, 80/52057, 80/70840, 80/139,383, 81/30125, 81/151,936, 82/34552, 82/68833, 82/204,036, 82/204,037, 83/134,634, 83/207,039, 84/60434, 84/101,650, 84/87450, 84/149,348, 84/182,785, 86/72040, 87/11455, 87/62157, 87/63149, 86/2151, 86/6652 and 86/48855 and in Research Disclosure 78/17051.

The efforts to develop colour photography materials in an even shorter time and at the same time to use chemicals which are easier to handle and pollute the environment less has led to considerable restrictions in the choice of the components of the system. Thus, silver halide emulsions used are those which are based largely or entirely on silver chloride, which means that the development time is shortened. It has furthermore been found that developer systems can be used largely or entirely without benzyl alcohol, without the colour density being reduced. This renders possible developer concentrates of few constituents, with shorter mixing times and with a lower toxicity of the spent developer. In order to achieve this aim of shortening the development time and reducing the benzyl alcohol, the following additives can be used:

(a) N-substituted hydroxylamines as antioxidants instead of the customary hydroxylamines,

(b) development accelerators, for example 1-aryl-3-pyrazolones, hydrazine derivatives, quaternary ammonium and phosphonium compounds or polyoxyalkylene compounds,

(c) triethanolamine as tar-combating agents,

(d) lithium salts, for example those of polystyrenesulfonates, and

(e) aromatic polyhydroxy compounds, for example sodium 5,6-dihydroxy-1,2,4-benzenetrisulfonate.

The compounds of the formula I and II can also be used in such rapidly-developing systems, such as in photographic layers based on silver chloride emulsions, and in systems which are developed entirely or largely without benzyl alcohol.

The following examples illustrate the preparation and use of the novel compounds in detail. In these, parts and percentages are parts by weight and percentages by weight. The temperatures are stated in °C.

EXAMPLE 1

27.0 g of cis-2,6-diphenylthian-4-ol (melting point 155°-156°, prepared in accordance with the method of C. A. R. Baxter, D. A. Whiting/J. Chem. Soc. 1968, 1176) and 27.8 g of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid are introduced into 350 ml of toluene, with stirring. After addition of 1.5 g of p-toluenesulfonic acid, the reaction mixture is heated to reflux for 12 hours, using a water separator. After cooling, the reaction solution is washed three times with 100 ml of water each time, dried over Na₂ SO₄ and evaporated in vacuo. The residue is recrystallized from ethanol. 4-[3-(3,5-Di-tert-butyl-4-hydroxyphenyl)-propionyloxy]-cis-2,6-diphenylthiane, which melts at 100° (compound No. 10), is obtained.

The esters listed in Table 1 are prepared in an analogous manner from the respective thiane-alcohols and phenolic carboxylic acids.

                                      TABLE 1                                      __________________________________________________________________________     Structural formula                Compound No.                                                                           Melting point                        __________________________________________________________________________      ##STR33##                         1      114°                           ##STR34##                         2       76°                           ##STR35##                         3      149°                           ##STR36##                         4       82°                           ##STR37##                         5      114°                           ##STR38##                         6      158°                           ##STR39##                         7      oil                                   ##STR40##                         9a 9b  102° 184°               ##STR41##                        10      110°                           ##STR42##                        12      188-190°                       ##STR43##                        13      116- 118°                      ##STR44##                        34      resin                                 ##STR45##                        35      157°                           ##STR46##                        36      resin                                 ##STR47##                        37      resin                                 ##STR48##                        42      144-146°                       ##STR49##                        43       97-99°                       __________________________________________________________________________      In this table:                                                                 Ph = phenyl                                                                    + = tert-butyl                                                           

EXAMPLE 2 Transesterification

115.4 g of 3-ethyl-3-hydroxymethyl-8,10-diphenyl-1,5-dioxa-9-thiaspiro-[5.5]undecane and 88.6 g of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are introduced into 800 ml of benzine (boiling range 110°-140°). About 50 ml of benzine are distilled off and the solution is allowed to cool to about 80°. After addition of 0.3 g of lithium amide, the reaction mixture is heated under a gentle stream of nitrogen until the methanol formed--together with a little benzine--distils over. After about 4 hours, the mixture is allowed to cool somewhat and 0.8 g of glacial acetic acid is added. After 10 minutes, 10 g of Tonsil are added and the mixture is stirred for a further 5 minutes and filtered. 3-[3-(3,5-Di-tert-butyl-4-hydroxyphenyl)-propionyloxy::ethyl]-3-ethyl-8,10-diphenyl-1,5-dioxa-9-thiaspiro[5.5]undecane crystallizes out of the filtrate on cooling and melts at 122° after drying (compound No. 19).

The esters listed in Table 2 are prepared in an analogous manner from the respective thiane-alcohols and methyl phenolcarboxylates.

                                      TABLE 2                                      __________________________________________________________________________                                                  Compound                                                                             Melting                     Structural formula                           No.   point                       __________________________________________________________________________      ##STR50##                                   15    resin                        ##STR51##                                   16    resin                        ##STR52##                                   17    resin                        ##STR53##                                   18    142-144°              ##STR54##                                   20    123°                  ##STR55##                                   21    resin                        ##STR56##                                   22    resin                        ##STR57##                                   23    oil                          ##STR58##                                   26    oil                          ##STR59##                                   27    oil                          ##STR60##                                   28    oil                          ##STR61##                                   29    oil                          ##STR62##                                   30    oil                          ##STR63##                                   31    oil                          ##STR64##                                   34    191-193°              ##STR65##                                   38    resin                        ##STR66##                                   40    resin                        ##STR67##                                   41    resin (85-95°)        ##STR68##                                   45    resin                        ##STR69##                                   50    163°                  ##STR70##                                   53    resin                        ##STR71##                                   54    resin                        ##STR72##                                   55    resin                        ##STR73##                                   56    69°                   ##STR74##                                   57    viscous oil                  ##STR75##                                   59    168°                 __________________________________________________________________________      In this table:                                                                 Ph =  phenyl                                                                   + = tert-butyl                                                           

EXAMPLE 3 Acylhydrazones

12.5 g of 3-(3-methyl-4-tert-butyl-4-hyroxyphenyl)-propionic acid hydrazide and 13.6 of 2,6-diphenyl-4-oxothiane are warmed to reflux in 300 ml of ethanol for 3 hours. The crude product which crystallizes out on cooling is filtered off and recrystallized from 500 ml of xylene. The resulting N-[-(3-methyl-5-tert-butyl-4-hydroxyphenyl)-propionylamido]-2,6-diphenyl-4-iminothiane of the formula ##STR76## melts at 211°-212° after drying in vacuo (compound No. 48).

N-[-(3,5-Di-tert-butyl-4-hydroxyphenyl)-propionylamido]-2,6-diphenyl-4-iminothiane, which melts at 266°, is prepared analogously from 14.6 g of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid hydrazide and 13.4 g of 2,6-diphenyl-4-oxothiane (compound No. 49).

EXAMPLE 4 Hydroxybenzylation of malonates

19 g of di-(2,2,6,6-tetramethylthian-4-yl)-malonate and 33.5 g of N,N-diethyl S-(3,5-di-tert-butyl-4-hydroxybenzyl) -dithiocarbamate are warmed to 50° in 150 ml of isopropanol. A solution of 3.6 g of NaOH in 20 ml of water is added dropwise at this temperature in the course of 30 minutes. The product starts to crystallize during the course of this. The mixture is heated at 50° for 1 hour and to reflux for 3 hours and then cooled to room temperature. The product which has precipitated is filtered off and recrystallized from acetone/acetonitrile. The resulting di(2,2,6,6-tetramethylthian-4-yl) bis-(3,5-di-tert-butyl-4-hydroxybenzyl)-malonate of the formula ##STR77## has a melting point of 220° (compound No. 51).

EXAMPLE 5 Acylation of the phenol group

1.5 g of 3-[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)-propionyloxymethyl]-3-methyl-8,10-diphenyl-1,5-dioxa-9-thiaspiro [5.5]undecane are dissolved in 20 ml of toluene. 2 ml of dimethylformamide and 0.63 g of trimethylamine are added. 0.6 g of methyl oxalyl chloride in 10 ml of toluene are added dropwise, while cooling to 0°. The mixture is stirred at room temperature for 6 hours. 20 ml of water are then added and the organic phase is separated off, dried and evaporated. The crude product of the formula ##STR78## remains as a residue in the form of a colourless oil (compound No. 46).

The compound of the formula ##STR79## is obtained as a yellowish oil (compound No. 52) in an analogous manner by reaction of 1.43 g of 3-[5-(3,5-dimethyl-2-hydroxyphenyl)-5-methylhexanoyloxy-methyl]-3-ethyl-8,10-diphenyl-1,5-dioxa-9-thiaspiro[5.5]-undecane.

EXAMPLE 6 Silylation of the phenol group

1.5 g of 3-[3(3-tert-butyl-5-methyl-4-hydroxyphenyl)-propionyloxymethyl]-8,10-diphenyl-1,5-dioxa-9-thiaspiro[5.5]-undecane and 0.94 g of 1,8-diazabicyclo[5.4O] undec-7-ene are dissolved in 20 ml of toluene. 0.54 g of trimethylchlorosilane in 10 ml of toluene is added dropwise, while cooling to 0°. The mixture is stirred at room temperature for 6 hours, 20 ml of water are then added and the organic phase is separated off, dried and evaporated. The oily residue is purified by chromatography on an Al₂ O₃ column. Hexane/ethyl acetate 9:1 is used as the eluting agent. The compound of the formula ##STR80## is obtained as a colourless oil (compound No. 47).

EXAMPLE 7 Stabilization of a yellow layer

0.087 g of the yellow coupler of the formula ##STR81## and 0.029 g of one of the light stabilizers shown in the following tables are dissolved in 2 ml of a mixture of dibutyl phthalate/ethyl acetate (1.5 g/100 ml). 9 ml of a 2.3% aqueous gelatin solution which has been brought to a pH of 6.5 and contains 1.744 g/l of the wetting agent Nekal® BX (Na diisobutylnaphthalene-sulfonate) are added to 1 ml of this solution. The mixture is then emulsified by means of ultra-sound for 3 minutes.

2 ml of a silver bromide emulsion with a silver content of 6 g per liter and 1 ml of a 0.7% aqueous solution of cyanuric acid dichloride as a gelatin hardener are added to 5 ml of the coupler emulsion thus obtained and the mixture is poured onto a plastic-coated paper of 13×18 cm. After a hardening time of 7 days, the samples are exposed with 125 lux.s through a silver step wedge and then processed in the Ektaprint 2 process from Kodak.

The colour step wedges thus obtained are irradiated in an Atlas Weather-Ometer behind a UV filter (Kodak 2C) with a 2500 W xenon lamp with a total of 60 kilojoules per cm².

The percentage decreases in colour density for an original colour density of 1.0 are shown in the following Tables 3 and 4.

                  TABLE 3                                                          ______________________________________                                         Stabilizer    Loss in density in %                                             Compound No.  (behind UV filter)                                               ______________________________________                                         none          23                                                               18            11                                                               42            12                                                               43            11                                                               44            12                                                               ______________________________________                                    

                  TABLE 4                                                          ______________________________________                                         Stabilizer    Loss in density in %                                             Compound No.  (behind UV filter)                                               ______________________________________                                         none          27                                                                9a           10                                                               10             9                                                               12            15                                                               13            11                                                               15             8                                                               16            11                                                               17             8                                                               19             9                                                               20             8                                                               21            15                                                               22            12                                                               26            12                                                               28             7                                                               29            13                                                               30            12                                                               31            12                                                               34            12                                                               35             9                                                               36            10                                                               37            14                                                               38             8                                                               40             8                                                               41             8                                                               46            11                                                               47            13                                                               48            14                                                               53            12                                                               54            14                                                               55            13                                                               56            10                                                               57            14                                                               58            11                                                               59             9                                                               ______________________________________                                    

EXAMPLE 8 0.091 g of the yellow coupler of the formula ##STR82## and 0.027 g of one of the light stabilizers shown in the following table are dissolved in 2 ml of a mixture of dibutyl phthalate/ethyl acetate (1.5 g/100 ml). 9 ml of a 2.3% aqueous gelatin solution which has been brought to a pH of 6.5 and contains 1.744 g/l of the wetting agent Nekal® BX are added to 1 ml of this solution. The mixture is then emulsified by means of ultra-sound for 3 minutes.

2 ml of a silver bromide emulsion with a silver content of 6 g per liter and 1 ml of a 0.7% aqueous solution of cyanuric acid dichloride as a gelatin hardener are added to 5 ml of the coupler emulsion thus obtained and the mixture is poured onto plastic-coated paper of 13×18 cm. After a hardening time of 7 days, the samples are exposed with 125 lux.s through a silver step wedge and then processed in the Ektaprint 2 process from Kodak.

The colour step wedges thus obtained are irradiated in an Atlas Weather-Ometer behind a UV filter (Kodak 2C) with a 2500 W xenon lamp with a total of 60 kilojoules per cm².

The percentage decreases in colour density for an original colour density of 1.0 are shown in Table 5.

                  TABLE 5                                                          ______________________________________                                         Stabilizer    Loss in density in %                                             Compound No.  (behind UV filter)                                               ______________________________________                                         none          18                                                                9a           10                                                               10            10                                                               19             8                                                               22            10                                                               34             9                                                               35             9                                                               38            11                                                               40             8                                                               ______________________________________                                    

EXAMPLE 9

0.076 g of the yellow coupler of the formula ##STR83## and 0.023 g of one of the light stabilizers shown in the following table are dissolved in 2 ml of a mixture of dibutyl phthalate/ethyl acetate (1.5 g/100 ml). 9 ml of a 2.3% aqueous gelatin solution which has been brought to a pH of 6.5 and contains 1.744 g/l of Nekal® BX are added to 1 ml of this solution. The mixture is then emulsified by means of ultrasound for 3 minutes.

2 ml of a silver bromide emulsion with a silver content of 6 g per liter and 1 ml of a 0.7% aqueous solution of cyanuric acid dichloride as a gelatin hardener are added to 5 ml of the coupler emulsion thus obtained and the mixture is poured onto a plastic-coated paper of 13×18 cm. After a hardening time of 7 days, the samples are exposed with 125 lux.s through a silver step wedge and then processed in the Ektaprint 2 process from Kodak.

The colour step wedges thus obtained are irradiated in an Atlas Weather-Ometer behind a UV filter (Kodak 2C) with a 2500 W xenon lamp with a total of 60 kilojoules per cm².

The percentage decreases in colour density for an original colour density of 1.0 are shown in the following Table 6.

                  TABLE 6                                                          ______________________________________                                         Stabilizer    Loss in density in %                                             Compound No.  (behind UV filter)                                               ______________________________________                                         none          21                                                               19             8                                                               34            10                                                               36            10                                                               38             9                                                               40             7                                                               ______________________________________                                    

EXAMPLE 10

0.038 g of the magenta coupler of the formula ##STR84## and 0.013 g of a light stabilizer shown in Table 7 are dissolved in 2 ml of a mixture of tricresyl phosphate/ethyl acetate (1 g/100 ml). 9 ml of a 2.3% aqueous gelatin solution which has been brought to a pH of 6.5 and contains 0.436 g/l of Nekal® BX are added to 1 ml of this solution. The mixture is then emulsified by means of ultra-sound for 3 minutes.

2 ml of a silver bromide emulsion with a silver content of 6 g per liter and 1 ml of a 0.7% aqueous solution of cyanuric acid dichloride as a gelatin hardener are added to 5 ml of the coupler emulsion thus obtained and the mixture is poured onto a plastic-coated paper of 13×18 cm. After a hardening time of 7 days, the samples are exposed with 125 lux.s through a silver step wedge and then processed in the Ektaprint 2 process from Kodak.

The colour step wedges thus obtained are stored in a climate cabinet for 28 days at 75° C. and 60% relative atmospheric humidity. The following Table 7 shows the percentage increase in colour density for an original colour density of 1.0.

                  TABLE 7                                                          ______________________________________                                         Stabilizer    Increase in density in %                                         Compound No.  (behind UV filter)                                               ______________________________________                                         none          41                                                                9a           28                                                               18            28                                                               42            31                                                               ______________________________________                                    

EXAMPLE 11

0.025 g of the cyan coupler of the formula ##STR85## and 0.025 g of one of the light stabilizers shown in Table 8 are dissolved in 2 ml of a mixture of dibutyl phthalate/ethyl acetate (0.8 g/100 ml). 9 ml of a 2.3% aqueous gelatin solution which has been brought to a pH of 6.5 and contains 0.872 g/l of Nekal® BX are added to 1 ml of this solution. The mixture is then emulsified by means of ultrasound for 3 minutes.

2 ml of a silver bromide emulsion with a silver content of 3 g per liter and 1 ml of a 0.7% aqueous solution of cyanuric acid dichloride as a gelatin hardener are added to 5 ml of the coupler emulsion thus obtained and the mixture is poured onto a plastic-coated paper of 13×18 cm. After a hardening time of 7 days, the samples are exposed with 125 lux.s through a silver step wedge and then processed in the Ektaprint 2 process from Kodak.

The colour step wedges thus obtained are irradiated in an Atlas Weather-Ometer behind a UV filter (Kodak 2C) with a 2500 W xenon lamp with a total of 60 kilojoules per cm².

The percentage decreases in colour density for an original colour density of 1.0 are shown in Table 8.

                  TABLE 8                                                          ______________________________________                                         Stabilizer    Loss in density in %                                             Compound No.  (behind UV filter)                                               ______________________________________                                         none          29                                                               18            19                                                               20            17                                                               ______________________________________                                    

EXAMPLE 12

0.025 g of the cyan coupler of the formula ##STR86## and 0.025 g of one of the light stabilizers shown in Table 9 are dissolved in 2 ml of a mixture of dibutyl phthalate/ethyl acetate (0.8 g/100 ml). 9 ml of a 2.3% aqueous gelatin solution which has been brought to a pH of 6.5 and contains 0.872 g/l of Nekal® BX are added to 1 ml of this solution. The mixture is then emulsified by means of ultrasound for 3 minutes. 2 ml of a silver bromide emulsion with a silver content of 3 g per liter and 1 ml of a 0.7% aqueous solution of cyanuric acid dichloride as a gelatin hardener are added to 5 ml of the coupler emulsion thus obtained and the mixture is poured onto a plastic-coated paper of 13×18 cm. After a hardening time of 7 days, the samples are exposed with 125 lux.s through a silver step wedge and then processed in the Ektaprint 2 process from Kodak.

The colour step wedges thus obtained are stored in a climate cabinet for 28 days at 75° C. and 60% relative atmospheric humidity.

The percentage decreases in colour density for an original colour density of 1.0 are shown in Table 9.

                  TABLE 9                                                          ______________________________________                                         Stabilizer    Loss in density in %                                             Compound No.  (behind the UV filter)                                           ______________________________________                                         none          50                                                               18            30                                                                9b           31                                                               ______________________________________                                    

EXAMPLE 13

0.031 g of the magenta coupler of the formula ##STR87## and the amount of one of the light stabilizers (or light stabilizer mixtures) shown in the following Table 10 are dissolved in 2 ml of a mixture of tricresyl phosphate/ethyl acetate (0.769 g/100 ml). 9.0 ml of a 2.3% aqueous gelatin solution which has been brought to a pH of 6.5 and contains 0.436 g/l of the wetting agent Nekal® BX (Na diisobutylnaphthalenesulfonate) are added to 1 ml of this solution. The mixture is then emulsified by means of ultra-sound for 3 minutes.

2 ml of silver bromide emulsion with a silver content of 6 g per liter and 1.0 ml of a 0.7% aqueous solution of cyanuric acid dichloride as a gelatin hardener are added to 5.0 ml of the coupler emulsion thus obtained and the mixture is poured onto a plastic-coated paper of 13×18 cm. After a hardening time of 7 days, the samples are exposed with 125 lux.s through a silver step wedge and then processed in the Ektaprint 2 process from Kodak.

The colour step wedges thus obtained are irradiated in an Atlas Weather-Ometer behind a UV filter (Kodak 2C) with a 2500 W xenon lamp with a total of 60 kilojoules per cm².

The increase in the yellow colour density in the non-exposed portion of the step wedge is shown in the following Table 10 (D_(B)).

                  TABLE 10                                                         ______________________________________                                         Stabilizer                                                                     Compound No.     Amount (g)                                                                               D.sub.B                                             ______________________________________                                         None             --        16%                                                 10               0.011     7%                                                  19               0.011     8%                                                  10+              0.0055    6%                                                  costabilizer A   0.0055                                                        19+              0.0055    5%                                                  costabilizer A   0.0055                                                        ______________________________________                                          costabilizer A = phenolic compound of the formula                              ##STR88##                                                                 

What is claimed is:
 1. A compound of the formula I or II ##STR89## in which n is 0, 1, or 2, R¹ and R² independently of one another are hydrogen or methyl, R³ and R⁴ independently of one another are hydrogen, C₁ -C₄ alkyl, phenyl, thienyl or phenyl which is substituted by 1 or 2 C₁ -C₈ alkyl groups, cyclohexyl, phenyl, C₇ -C₉ phenylalkyl, hydroxyl, C₁ -C₁₈ alkoxy or halogen, R⁵ and R⁶ independently of one another are hydrogen, C₁ -C₄ alkyl, phenyl, --COO(C₁ -C₁₈ alkyl), --CO--CH₃ or --CO-phenyl, R⁷ is hydrogen, C₁ -C₈ alkyl or one of the groups --CO--R¹¹, --CO--COO(C₁ -C₄ -alkyl), --SO₂ --R¹², --CON(R¹³)(R¹⁴), --Si(R¹⁵)(R¹⁶)(R¹⁷) or ##STR90## R⁸ and R⁹ independently of one another are hydrogen, C₁ -C₁₂ alkyl, C₇ -C₉ phenylalkyl, C₅ -C₈ cycloalkyl or phenyl, R¹⁰ is hydrogen, --OR⁷ or a group of the formula III ##STR91## in which M is a direct bond, --O--, --S--, --S--S--, --CH₂ --, --CH(C₁ -C₈ alkyl)- or --C(CH₃)₂ --, R¹¹ is C₁ -C₂₀ alkyl, C₃ -C₂₀ alkenyl, C₅ -C₁₂ cycloalkyl, C₇ -C₁₃ phenylalkyl, phenyl or naphthyl, R¹² is C₁ -C₁₂ alkyl, phenyl, naphthyl or phenyl or naphthyl substituted by C₇ -C₂₄ alkyl, R¹³ is hydrogen, C₁ -C₁₂ alkyl or cyclohexyl, R¹⁴ is C₁ -C₁₂ alkyl, phenyl, naphthyl, C₁ -C₁₂ alkylsubstituted phenyl or naphthyl or cyclohexyl, R¹⁵, R¹⁶ and R¹⁷ independently of one another are C₁ -C₁₂ alkyl, C₃ -C₁₂ alkenyl, phenyl, cyclohexyl or benzyl, T is a trivalent group which completes the ring to give a thiane ring and is one of the following groups: ##STR92## in which R¹⁸ is hydrogen, C₁ -C₁₂ alkyl, benzyl, cyclohexyl or phenyl and R¹⁹ is hydrogen or C₁ -C₄ alkyl, Z is a divalent bonding member between T and the phenol radical and is one of the following groups: ##STR93## the carbonyl group of which is bonded to T and in which R²⁰ is C₁ -C₁₄ -alkylene, R²¹ is hydrogen, C₁ -C₁₂ alkyl, phenyl, C₇ -C₉ phenylalkyl or a group of the formula IV ##STR94## and R²² is a group --O(C₁ -C₄ alkyl) or a group of the formula V ##STR95##
 2. A compound according to claim 1 of the formula I or II, in which n is 0 or 2, R¹ and R² are hydrogen or methyl, R³ and R⁴ independently of one another are methyl, phenyl, thienyl or phenyl which is substituted by one or two C₁ -C₄ alkyl groups, cyclohexyl, hydroxyl, C₁ -C₄ alkoxy or chlorine, R⁵ and R⁶ independently of one another are hydrogen, --COO(C₁ -C₄ alkyl) or --COCH₃, R⁷ is hydrogen or a group --CO--R¹¹, --CO--COO(C₁ -C₄ -alkyl), --Si(CH₃)₃ or ##STR96## R⁸ and R⁹ independently of one another are C₁ -C₈ alkyl, C₇ -C₉ phenylalkyl, cyclohexyl or phenyl, R¹⁰ is hydrogen, --OR⁷ or a group of the formula III, in which M is --S--, --CH₂ --, --CH(C₁ -C₄ alkyl) or --C(CH₃)₂ --, R¹¹ is C₁ -C₁₂ alkyl or phenyl, T is one of the following trivalent groups: ##STR97## in which R¹⁹ is C₁ -C₄ alkyl, and Z is one of the following divalent groups: ##STR98## the carbonyl group of which is bonded to T and in which R²⁰ is C₁ -C₁₄ -alkylene, R²¹ is C₁ -C₈ alkyl, benzyl or a group of the formula IV and R²² is a groups --O(C₁ -C₄ alkyl) or a group of the formula V.
 3. A compound according to claim 1 of the formula I or II, in which n is 0 or 2, R¹ and R² are hydrogen or methyl, R³ and R⁴ are methyl, phenyl, thienyl or phenyl which is substituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy, hydroxyl or chlorine, R⁵ and R⁶ are hydrogen, R⁷ is hydrogen or a group ##STR99## R⁸ and R⁹ independently of one another are hydrogen, C₁ -C₄ alkyl, cyclohexyl or phenyl, R¹⁰ is hydrogen, T is one of the following trivalent groups: ##STR100## in which R¹⁹ is C₁ -C₄ alkyl, and Z is one of the following divalent groups: ##STR101## the carbonyl group of which is bonded to T and in which R²⁰ is C₁ -C₈ -alkylene, R²¹ is C₁ -C₈ alkyl, benzyl or a group of the formula IV and R²² is --O(C₁ -C₄ alkyl) or a group of the formula V.
 4. A compound according to claim 1 of the formula I or II, in which R¹, R², R⁵ and R⁶ are hydrogen and the other symbols are as defined in claim
 1. 5. A compound according to claim 1 of the formula I.
 6. A compound according to claim 1 of the formula I or II, in which n is 0 (zero).
 7. The compound according to claim 1, 3-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionyloxymethyl]-3-ethyl-8,10-diphenyl-1,5-dioxa-9-thiaspiro[5.5]undecane. 